Phototypography



UNITED STATES PATENT OF ICE.

JOHN N. LUTZ, OF PORTSMOUTH, OHIO.

PHOTOTYPOGRAPHY.

SPECIFICATION forming part of Letters Patent No. 240,262, dated April19, 1881.

Application filed January 11 1881. (No specimens.)

To all whom tt may concern:

Be it known that I, JOHN N. LUTZ, a citizen of the United States,residing at Portsmouth, in the county of Scioto and State of Ohio, haveinvented certain new and useful Improvements in Phototypography; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to improvements in the art of producingphotographic pictures upon wood, especially such as are to assist engravers. The preparation of the wood for this purpose has been hithertoaccomplished by processes both expensive and tedious, and the purpose ofthis invention is to avoid the difficulties heretofore met with andprovide a process whereby a photographic picture of a very superiorcharacter can be obtained at a merely nominal price.

Ablock of wood of proper quality and proper size is first coated withwhite watercolor and water, which are rubbed over the wood until a whiteand perfectly smooth surface is produced, and the excess is thenremoved. After the wood has been whitened and smoothed it is thentreated with the following solution: I take five grains of citric acid,five grains of chloride of ammonium, and twelve grains of gelatine, anddissolve and thoroughlymix them in one ounce of water. I The solution isheated, and it is then poured over the surface of the block. It is lefton the block from three to five minutes, and the block is then allowedto dry.

One great advantage incident to the above solution is that it can bekept for a long time, and can therefore be prepared in large quantitiesand can be put upon the market as a manufacture.

After the block is dry it is treated with the following preparation:Nitrate of silver is dissolved in water in the proportion of fortygrains of the former to one ounce of the latter. The solution is thenfiltered through paper. and the block is treated with it in a mannersimilar to that described above.- After the block has been subjected tothe action of the latter solution for two or three minutes it is driedin the dark, as the block is now sensitive to light. After it is dry itis treated for about ten minutes with ammonia, and it is then ready toreceive the impression from the negative. After the impression has beentaken and the negative removed the block is washed and subjected to ahypo-bath for about five minutes, after which it is again washed, and isthen ready for the engraver.

The most important part of my process is that comprised in the secondstep, or the application of chloride of ammonium, gelatine, water, andcitric acid, 850. By means of this preparation I obtain a much clearerimpression than can be procured by the ordinary agents. It keeps thesilver from sinking while the light is acting through the negative. Italso gives a vigor and brilliancy to the picture, producing very clearwhite in the lighter portion and deep black in the shadow.

I do not wish to be understood as claiming, broadly, the use of citricacid alone as an ingredient in preparations for photographing upon woodfor engraving, as I am-aware that various acids have been heretoforeused for this purpose; but I believe myself to be the first to haveemployed the hereinbefore-described preparations in the exact manner andin the sequence which has been set forth.

What I claim i The herein-described process for preparing Wood toreceive a photographic impression for engraving, which consists in firstapplying to the surface of the wood an enameling or whiteningpreparation, then a preparation consisting of chloride of ammonium,citric acid, gelatine, and Water, insubstantially the proportionsspecified, then a silver sensitizing preparation, and finally ammonia,substantially in the manner and for the purposes set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN N. LUTZ. Witnesses:

I. N. ZOELLNER, O. A. ZOELLNER.

